1. Field of the Invention
The invention relates to a substrate, more particularly, to a substrate with high fracture strength.
2. Description of the Prior Art
With continuing development of semiconductor processing technologies, more and more semiconducting components have been researched and produced. In general, semiconducting components are implemented by forming several layer structures on a substrate. Therefore, the substrate has become the basic and must component.
For example, the solar cell in prior art usually utilizing a semiconductor wafer (e.g. Si wafer) as the substrate. However, the Si wafer belongs to the brittle material, which is easy to fracture by an outer impact, especially the outer impact in the assembling procedure of the solar cell. Besides the solar cell, Si wafers are generally utilized in various semiconductor products. With the increasing demanding of the semiconductor components, the supplement of the Si wafer is tightened. Therefore, it becomes an urgent problem about how to prevent the Si wafer material from wasted (e.g. fractured by an outer impact) and to elevate the yield of the process. In the example of the solar cell, if it is formed on a substrate with high fracture strength, the possibility of that the substrate happens to break in the assembling procedure can be eliminated.
Please refer to FIG. 1A and FIG. 1B. FIG. 1A to FIG. 1B are pictures shot in the fracture strength test on a test piece of a Si wafer in prior art. The test piece of the Si wafer is made of monocrystalline silicon. During the period of stressing, the stress may concentrate on some particular areas of the test piece, where some cracks appears. With the stress increasing, the crack propagation becomes more obvious, and finally it will break the test piece into several pieces, as shown in FIG. 1B.
The test piece of the Si wafer in prior art will have the stress concentrated within the particular areas of the test piece. If the stress can be overspread to whole Si test piece evenly during the test, it may elevate the fracture strength.
Therefore, the invention discloses a substrate, so as to solve said problems.